In recent years, a transdermal absorption type patch preparation for transdermal administration of a drug by adhesion of an adhesive sheet containing the drug to the skin has been put to practical use (such “transdermal absorption type adhesive preparation” is also referred to as a “transdermal absorption patch”, and to be also called in the following description as a “transdermal absorption patch”).
A transdermal absorption patch is basically formed by laminating an adhesive layer containing a drug on one surface of a plastic support such as polyester, polyethylene and the like, and coating an exposed surface of the adhesive layer with a separator. Generally, such a transdermal absorption patch is independently packed with a package (film) impermeable to water, gas and the like to prevent volatilization of the drug contained in the adhesive layer and influence of humidity.
However, in an individually packed transdermal absorption patch, an adhesive may stick out from the edge of the patch, attach to the inside of the package (film) and, when in use, make it difficult to take out the transdermal absorption patch from the package. Particularly, when a transdermal absorption promoter, a plasticizer, a tackifier, a liquid component and the like are contained in an adhesive layer, the adhesive easily sticks out from the edge and taking out of the transdermal absorption patch becomes markedly difficult.
To solve the above-mentioned inconveniences, a blister pack, namely, a blister (container having a concave portion to be a concave to accommodate the content) is often employed, where a transdermal absorption patch is placed in the concave recess, and a cover sheet is adhered to the outer circumference of the blister to enclose the patch.
For hygiene or medical goods and pharmaceutical products, it is a recent tendency to place an importance on a package structure preventing easy opening by children (what is called a “child-proof package structure”). In the case of blister packaging, easy opening is prevented by the use of a cover sheet having a high tear strength, increased adhesion between a blister and a cover sheet and the like. In some cases, such packages are difficult to open even for adults without a knife or scissors. In general, blister packaged goods require use of a knife, scissors etc. to tear open the package and take out the contents. To open a blister packaged good, therefore, it is substantially necessary to always carry a knife, scissors and the like. In addition, when a package is torn with a sharp blade such as a knife, scissors and the like, problems occur since the contents may also be cut, and one who intends to open a blister packaged good may be injured with the blade. Therefore, child-proof package structures that can be opened without using a knife or scissors have been proposed in recent years. However, all of them are problematic in that the structure is complicated or opening operation is complicated (see patent document 1, patent document 2).    patent document 1: JP-T-2003-500305    patent document 2: JP-A-2008-133055